Question about fluted walls on 2 story homes...

[Kroke]

I want to design a 2 story home that has the upper level walls set in 2" from the walls below so that the builders can build a 'skirt' around the peremiter of the second floor exterior that angles from the lower level inward those 2" and up about 2'-0" or so. The one question I'm wondering about is the shear. Usually when building the second floor walls in the field, the exterior sheating comes down and ties the second story walls to the rim joist below, shearing it up.

If the walls above are inset those 2", how is are they sheared to the lower level? I know they're built this way but how is the shear taken care of? Straps or what? I know this is more of an engineering standpoint but I wanted to get opinions first before I go into engineering in case it might be an issue.

Any thoughts would be appriciated. Thanks,

JJ

[Les Therrien]

Around here that wouldn't be a big deal.
Can you not just add solid blocking underneath the upper wall?

[Kroke]

Ok, thanks, I managed to get ahold of my engineer finally. He said it's not a big deal, the builders would have to strap (if necessarry) from the upper level studs through the floor sheating down to the lower level studs. Kind of a pain for the builders, but hey, I'm on this end of the plans, right? hehe.

[Les Therrien]

that's what I say!

I only draw the lines!!!

[Wes Macaulay]

I think most joist systems want 38mm (1.5") of end bearing. As long as you have that, you're likely to have engineering okayed. TJI docs usually ask for no more than this.

[Kroke]

Wes,
I think I know what you're saying. There should still be 3.5" of bearing for the I-joists. Maybe they'll even have to add squash blocks between the joists since the upper wall won't be bearing on the rim joist. I didn't ask that, but I will once it gets more developed.

What actually gave me this inspriation was my old roommate wanted me to 3D model a home with this feature. I was wondering "How would I model this in Revit?" Then I saw either a tutorial or a link from here of a revit file showing compound walls with these built in. I must say, it looked way too simple, so I thought I would try it on this side project I just landed. And for once, I decided to tell the client "Here's my price...." (Usually followed by a cringe and I dicker with them, but no more, my time is more valuable to have free time than doing this in my spare time, anyhow, they accepted my proposal, so I will make some good dough from this one, yay!)

[Wes Macaulay]

They might... though with double top plates most manufacturers, if you're within a certain span, may not even require blocking between studs...

Our National Building Code I believe asks for a minimum bearing, and a maximum allowable span before the bearing has to be engineered. But your codes are probably totally different!

[SkiSouth]

Another option to offer the home owner and builders would be to build the lower floors of 2x6 walls and the upper with 2x4. This will keep the load vertical on the studs. There is a moment condition (although a small one) at the joint on the interior from the exterior wind load with the offset stud.

[Les Therrien]

Ontario requires for joists systems to have 1.5" of minimum bearing as Wes said. We require minimum 3.5" of bearring for beams.
Though I have had situations where engineered joists required a larger bearing due to large spans.

[Kroke]

Another option to offer the home owner and builders would be to build the lower floors of 2x6 walls and the upper with 2x4.

I've never desinged or framed a home in Oregon with 2x4 exterior walls, otherwise, that would be a good solution.

[adegnan]

Kroke,
Just use 1 1/2" foam sheathing for your wall sheathing, and dense-pack cellulose in the wall cavities. You'll have no problem with R-values! And you'll have one excellent, tight house!